The present invention relates to a spool case unit which is provided for a camera using a long and narrow film, the spool case having a spool shaft housed therein for winding the film loaded from outside into the camera, and a camera having such a spool case unit.
In connection with the conventional spool case unit, the main structural elements are formed of a metal or synthetic resin material, as an integral unit, together with the frame of the camera which uses the spool case unit, by injection molding.
Recently, there is a great demand for the reduction of the size of the external dimension of the camera and its weight. However, with the conventional spool case unit which includes the main structural elements formed integrally with the frame of the camera as described above, it is very difficult to satisfy the above described demand. More specifically, there is a limitation in reducing the thickness of the main structural elements, under consideration of the flow of the molten metal or synthetic resin during the injection molding process. In order to reduce the external dimension of the camera and its weight further than the present level, the conventional method of manufacturing a spool case unit, must be changed.
Jpn. Pat. Appln. KOKAI Publication No. 7-20565 discloses a technique in which a part of the side wall of the outer shell, the shell being a main structural element of the spool case unit, is made of an elastic thin plate. The part of the side wall is located adjacent to the lens barrel of the camera. This structure makes it possible to place the spool case unit slightly closer to the lens barrel than in the conventional camera, and contributes to the slight reduction of the weight of the spool case unit.
Jpn. Pat. Appln. KOKAI Publication No. 4-340529 discloses a structure in which a motor is placed within the spool shaft of the spool case unit in order to reduce the size of the camera. According to the structure disclosed in this publication, the outer shell of the spool case unit is composed of two-divided upper and lower halves. In order to assemble the spool case unit, the motor is fixed with screws at a predetermined position in the upper half of the outer shell of the spool case unit, and then the lower half of the outer shell is fixed to the upper half while the center hole of the spool is rotatably fitted on the circumference of the motor. Thus, the structure of the spool case unit disclosed in Jpn. Pat. Appln. KOKAI Publication No. 4-340529 makes an assembly of the camera complicate. Further, this structure does not exhibit any weight reducing technique.
This invention is derived from the above described circumstances, and an object of the present invention is to provide a spool case unit for a camera, which has a simple structure, can be easily assembled, and enables a reduction of the external dimension of the camera and its weight, as well as a camera which includes the above described spool case unit.